Subcircular in plan, it measures roughly 26 metres north to south and just over 23 metres east to west, defined by a drystone wall standing between one and one and a half metres high. Drystone construction means exactly what it sounds like: stone laid without mortar, relying on careful coursing and the weight of the material itself to hold form. What makes this particular wall notable is what it lacks. It is not faced, meaning the stones have not been dressed or arranged to present a neat outer surface, and there is no collapsed spread of rubble at the base, which would normally suggest a structure that had partially fallen in on itself over time. There are also no traces of foundations from any earlier building beneath or within it.